Air pollution is killing an average of 4,000 people a day in China, according to researchers who cited coal-burning as the likely principal cause.
Deaths related to the main pollutant, tiny particles known as PM2.5s that can trigger heart attacks, strokes, lung cancer and asthma, total 1.6 million a year, or 17 percent of China’s mortality level, according to the study by Berkeley Earth, an independent research group funded largely by educational grants. It was published Thursday in the online peer-reviewed journal PLOS One from the Public Library of Science.
“When I was last in Beijing, pollution was at the hazardous level: Every hour of exposure reduced my life expectancy by 20 minutes,” Richard Muller, scientific director of Berkeley Earth and a co-author of the paper, said in an e-mail. “It’s as if every man, woman and child smoked 1.5 cigarettes each hour.”
Chinese authorities have acknowledged the air pollution situation after heavy smog enveloped swathes of the nation including Beijing and Shanghai in recent years. They’ve adopted air quality standards, introduced monitoring stations and cleaner standards for transportation fuel while shutting coal plants and moving factories out of cities.
Muller and co-author Robert Rohde analyzed four months of hourly data for some 1,500 ground stations in China. They then employed a model used by the World Health Organization to calculate the disease burden.
They found that 92 percent of China’s population experienced at least 120 hours of unhealthy air during the April 5, 2014, to Aug. 5, 2015 study period. For 38 percent of the population, the average pollution level across the entire four-month period was deemed unhealthy.
About 90 percent of the 161 cities whose air quality was monitored in 2014 failed to meet official standards, according to China’s National Bureau of Statistics.
The Berkeley Earth researchers also examined where the pollutants were detected and concluded that the sources of PM2.5s matching those for sulfur dioxide suggests most of the pollution comes from burning coal.
“Sources of pollution are widespread but are particularly intense in a northeast corridor that extends from near Shanghai to north of Beijing,” the researchers wrote. “Extensive pollution is not surprising since particulate matter can remain airborne for days to weeks and travel thousands of kilometers.”
China gets about 64 percent of its primary energy from coal, according to National Energy Administration data. It’s closing the dirtiest plants while still planning new, cleaner ones. The country is expected to shut 60 gigawatts of plants from 2016 to 2020 though three times as many plants are scheduled to be built using newer technology, according to Sophie Lu, a Bloomberg New Energy finance analyst in Beijing.
Berkeley Earth is funded mainly by educational grants and supported by the U.S. Department of Energy. It was started in 2010 to examine global temperatures to see if there was merit in the concerns of skeptics of climate change and has since expanded research to other areas of global warming and air pollution.